"He is absolutely a prospect at heavyweight," Deas told Newshub. "He did have some problems, but those have been fixed."

The problems Deas refers to almost cost Fa his career, if not his life. The 29-year-old was found to have low iron and haemoglobin and doctors couldn't believe he got through 10 rounds with oxygen struggling to pass through his body.

He had minor gastric surgery and thankfully, biopsies were clear of cancer.

"I didn't bring that up with him, but if he'd had bowel cancer, I don't know where that goes to."

Now in the clear and healthy, Fa has eyes only on heavyweight gold and Deas believes he has all the skills to stand opposite Wilder - not only in a three-round sparring session, but a even heavyweight championship fight.

"Totally different guy,” he told Newshub. “It's amazing when you have all your facilities, all your vitamins and your minerals, and your body chemistry is working the right way, after it hasn't been.

"It's an amazing thing.

"Usually, we only bring sparring partners in for one week at a time, but Junior will actually be here for an entire month

"He just completed the first sparring week and he got a lot of good rounds.

"He's very competitive, talented and very athletic as well, so it's great for us."